HUMAN OCULAR RESPONSES TO TRANSLATION OF THE OBSERVER AND OF THE SCENE - DEPENDENCE ON VIEWING DISTANCE
HUMAN OCULAR RESPONSES TO TRANSLATION OF THE OBSERVER AND OF THE SCENE - DEPENDENCE ON VIEWING DISTANCE
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DOI：
10.1007/bf02738407
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发表时间：
1994-08-01
影响因子：
2
通讯作者：
CARL, JR
中科院分区：
文献类型：
--
作者：
BUSETTINI, C;MILES, FA;CARL, JR
最近在猴子身上的实验表明，观察者或视觉场景的短暂平移引起的眼动是观看距离的倒数的线性函数。对于观察者的移动，房间是黑暗的，反应归因于通过耳石器官感知运动的平移前庭-眼睛反射(TVOR)；对于引发眼球跟随的场景移动，场景被投影并在大小和速度上进行调整，使得视网膜刺激在所有距离都是相同的。对观看距离的共同依赖与TVOR和眼球跟随是协同的和共享中心通路的假设是一致的。目前的实验在人类受试者身上寻找这种对观看距离的依赖关系。当受试者在黑暗中沿着耳间轴线短暂加速时，受试者会产生补偿性眼球运动，这种眼球运动也是先前注视目标的观察距离的倒数的线性函数。这些反应被归因于TVOR，比以前使用类似方法从猴子身上记录的反应要弱一些。当人类受试者面对投射有图案的图像的切线屏幕时，这些图像的短暂运动引发了眼睛跟随反应，只有在低速刺激(10度/S)下，这种反应在统计学上表现出对观看距离的显著依赖。这种依赖性充其量是弱的，而且与TVOR的方向相反，即响应随着观看距离的增加而增加。我们认为，在生成观看距离的内部估计时，受试者可能在眼球跟随范式中使用了一种令人困惑的线索-投影场景的大小-在这些实验中，这与观看距离直接不同(为了保持视网膜图像的大小)。当受试者的运动与场景的运动随机交错时--以鼓励自我运动的预期--眼球跟随对观看距离的依赖发生了显著变化：在更快的速度刺激(40度/S)下，许多反应(63%)现在随着观看距离的减少而显著增加，尽管没有TVOR那么强烈。我们认为，在我们的实验情境中，对运动的预期导致被试更重视提供真实距离信息的线索，如收敛和调节：线索的选择与背景有关。
Recent experiments on monkeys have indicated that the eye movements induced by brief translation of either the observer or the visual scene are a linear function of the inverse of the viewing distance. For the movements of the observer, the room was dark and responses were attributed to a translational vestibule-ocular reflex (TVOR) that senses the motion through the otolith organs; for the movements of the scene, which elicit ocular following, the scene was projected and adjusted in size and speed so that the retinal stimulation was the same at all distances. The shared dependence on viewing distance was consistent with the hypothesis that the TVOR and ocular following are synergistic and share central pathways. The present experiments looked for such dependencies on viewing distance in human subjects. When briefly accelerated along the interaural axis in the dark, human subjects generated compensatory eye movements that were also a linear function of the inverse of the viewing distance to a previously fixated target. These responses, which were attributed to the TVOR, were somewhat weaker than those previously recorded from monkeys using similar methods. When human subjects faced a tangent screen onto which patterned images were projected, brief motion of those images evoked ocular following responses that showed statistically significant dependence on viewing distance only with low-speed stimuli (10 degrees/s). This dependence was at best weak and in the reverse direction of that seen with the TVOR, i.e., responses increased as viewing distance increased. We suggest that in generating an internal estimate of viewing distance subjects may have used a confounding cue in the ocular-following paradigm the size of the projected scene - which was varied directly with the viewing distance in these experiments (in order to preserve the size of the retinal image). When movements of the subject were randomly interleaved with the movements of the scene - to encourage the expectation of ego-motion - the dependence of ocular following on viewing distance altered significantly: with higher speed stimuli (40 degrees/s) many responses (63%) now increased significantly as viewing distance decreased, though less vigorously than the TVOR. We suggest that the expectation of motion results in the subject placing greater weight on cues such as vergence and accommodation that provide veridical distance information in our experimental situation: cue selection is context specific.